Some people manage to do everything the hard way

ips.rb

require 'benchmark/ips'

SIZE = 10

Benchmark.ips do |x|
  x.report('insane') do
    [0].cycle.take(SIZE)
  end

  x.report('sane') do
    Array.new(SIZE, 0)
  end

  x.report('alternative') do
    [0] * SIZE
  end
end

=begin
ruby rees.rb
Warming up --------------------------------------
              insane    62.407k i/100ms
                sane   140.605k i/100ms
         alternative   132.611k i/100ms
Calculating -------------------------------------
              insane    831.289k (± 4.1%) i/s -      4.181M in   5.038624s
                sane      2.723M (± 5.1%) i/s -     13.639M in   5.021281s
         alternative      2.289M (± 4.4%) i/s -     11.537M in   5.049794s
=end

mem.rb

require 'benchmark/memory'

SIZE = 10

Benchmark.memory do |x|
  x.report('insane') do
    [0].cycle.take(SIZE)
  end

  x.report('sane') do
    Array.new(SIZE, 0)
  end

  x.report('alternative') do
    [0] * SIZE
  end
end

=begin
ruby rees_mem.rb
Calculating -------------------------------------
              insane   288.000  memsize (     0.000  retained)
                         3.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)
                sane   120.000  memsize (     0.000  retained)
                         1.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)
         alternative   160.000  memsize (     0.000  retained)
                         2.000  objects (     0.000  retained)
                         0.000  strings (     0.000  retained)
=end